I can see how to test if the current visitor is logged in, but now how to test if a specific user is logged in. There is not much in the way of documentation on line, is there some published some where.
I want to build a button that, if the specific user is not logged in, it behaves one way, if the specific user is logged in it behaves another.
All I need to know is how to query for the login state of that specific user.
Thanks